With the increase of mobile communication demands of people and the development of technology, quality and efficiency of 2/3G communication networks have been incapable of satisfying the demands of people. Therefore, 4G-LTE networks are gradually started to be applied. During LTE network deployment, low network quality and poor stability are caused by instable or defective devices or terminals. Thus, operators urgently need a signaling monitoring system which can monitor and assess primary devices to facilitate the quality improvement of networks.
In a Long Term Evolution LTE network, an S1-MME interface is an interface between an eNodeB (evolved NodeB, also called as a base station) to an EPC (Evolved Packet Core) MME (Mobility Management Entity), and is an associated node from a wireless access network to a core network. The signaling monitoring system of the S1-MME interface plays an important role in monitoring and guaranteeing the quality and stability of the wireless network and the core network of LTE and interaction processes therebetween.
In consideration of air interface security, subscriber identities International Mobile Subscriber Identities IMSIs are prevented from being directly transmitted as much as possible in S1-MME interface signaling and will be replaced with temporary subscriber identities Globally Unique Temporary UE Identities GUTIs in a signaling process. However, GUTIs are temporary identities, and will be allocated to different subscribers again and cannot directly correspond to subscribers, resulting that bills generated by the S1-MME interface signaling monitoring system frequently lack IMSIs, and cannot be directly associated to subscribers. Therefore, use demands of operators cannot be satisfied. Specifically, in signaling of an S1-MME interface, basically temporary subscriber identities are always used and final subscriber identities IMSIs are not used. MMEs store IMSI information as it is received for once, GUTIs will be used in subsequent processes and the IMSI information will be saved for a very long time even though user terminals are powered off and detached. Supposing that a user terminal is always in a same base station area in one month, i.e., is located on a same MME, all S1-MME interface signaling processes of the terminal in one month will only use GUTIs and do not carry an IMSI. Only when the IMSI at the MME does not exist, signaling for requesting the IMSI is initiated once. Once the IMSI is acquired again, subsequent processes continuously use GUTIs. Only in special scenarios that the terminal is powered on for the first time, and the terminal is switched between different MMEs and the terminal is powered off for many days, there is no IMSI information at the MME. These scenarios rarely occur and temporary identities GUTIs are always used in subsequent processes after any one of these scenarios occurs once. That causes that the IMSI cannot be acquired from most signaling processes of the S1-MME interface. As a result, bills generated by the S1-MME interface signaling monitoring system frequently lack IMSIs and cannot be directly associated to subscribers.